C++线程池（Windows）

#ifndef _ThreadPool_H_#define _ThreadPool_H_#pragma warning(disable: 4530)#pragma warning(disable: 4786)#include <cassert>#include <vector>#include <queue>#include <windows.h>using namespace std;class ThreadJob //工作基类{public://供线程池调用的虚函数virtual void DoJob(void *pPara) = 0;};class ThreadPool{public://dwNum 线程池规模ThreadPool(DWORD dwNum = 4) : _lThreadNum(0), _lRunningNum(0){InitializeCriticalSection(&_csThreadVector);InitializeCriticalSection(&_csWorkQueue);_EventComplete = CreateEvent(0, false, false, NULL);_EventEnd = CreateEvent(0, true, false, NULL);_SemaphoreCall = CreateSemaphore(0, 0, 0x7FFFFFFF, NULL);_SemaphoreDel = CreateSemaphore(0, 0, 0x7FFFFFFF, NULL);assert(_SemaphoreCall != INVALID_HANDLE_VALUE);assert(_EventComplete != INVALID_HANDLE_VALUE);assert(_EventEnd != INVALID_HANDLE_VALUE);assert(_SemaphoreDel != INVALID_HANDLE_VALUE);AdjustSize(dwNum <= 0 ? 4 : dwNum);}~ThreadPool(){DeleteCriticalSection(&_csWorkQueue);CloseHandle(_EventEnd);CloseHandle(_EventComplete);CloseHandle(_SemaphoreCall);CloseHandle(_SemaphoreDel);vector<ThreadItem*>::iterator iter;for(iter = _ThreadVector.begin(); iter != _ThreadVector.end(); iter++){if(*iter)delete *iter;}DeleteCriticalSection(&_csThreadVector);}//调整线程池规模int AdjustSize(int iNum){if(iNum > 0){ThreadItem *pNew;EnterCriticalSection(&_csThreadVector);for(int _i=0; _i<iNum; _i++){_ThreadVector.push_back(pNew = new ThreadItem(this));assert(pNew);pNew->_Handle = CreateThread(NULL, 0, DefaultJobProc, pNew, 0, NULL);// set prioritySetThreadPriority(pNew->_Handle, THREAD_PRIORITY_BELOW_NORMAL);assert(pNew->_Handle);}LeaveCriticalSection(&_csThreadVector);}else{iNum *= -1;ReleaseSemaphore(_SemaphoreDel, iNum > _lThreadNum ? _lThreadNum : iNum, NULL);}return (int)_lThreadNum;}//调用线程池void Call(void (*pFunc)(void *), void *pPara = NULL){assert(pFunc);EnterCriticalSection(&_csWorkQueue);_JobQueue.push(new JobItem(pFunc, pPara));LeaveCriticalSection(&_csWorkQueue);ReleaseSemaphore(_SemaphoreCall, 1, NULL);}//调用线程池inline void Call(ThreadJob * p, void *pPara = NULL){Call(CallProc, new CallProcPara(p, pPara));}//结束线程池, 并同步等待bool EndAndWait(DWORD dwWaitTime = INFINITE){SetEvent(_EventEnd);return WaitForSingleObject(_EventComplete, dwWaitTime) == WAIT_OBJECT_0;}//结束线程池inline void End(){SetEvent(_EventEnd);}inline DWORD Size(){return (DWORD)_lThreadNum;}inline DWORD GetRunningSize(){return (DWORD)_lRunningNum;}bool IsRunning(){return _lRunningNum > 0;}protected://工作线程static DWORD WINAPI DefaultJobProc(LPVOID lpParameter = NULL){ThreadItem *pThread = static_cast<ThreadItem*>(lpParameter);assert(pThread);ThreadPool *pThreadPoolObj = pThread->_pThis;assert(pThreadPoolObj);InterlockedIncrement(&pThreadPoolObj->_lThreadNum);HANDLE hWaitHandle[3];hWaitHandle[0] = pThreadPoolObj->_SemaphoreCall;hWaitHandle[1] = pThreadPoolObj->_SemaphoreDel;hWaitHandle[2] = pThreadPoolObj->_EventEnd;JobItem * pJob;bool fHasJob;for(;;){DWORD wr = WaitForMultipleObjects(3, hWaitHandle, false, INFINITE);//响应删除线程信号if(wr == WAIT_OBJECT_0 + 1)break;//从队列里取得用户作业EnterCriticalSection(&pThreadPoolObj->_csWorkQueue);if(fHasJob = !pThreadPoolObj->_JobQueue.empty()){pJob = pThreadPoolObj->_JobQueue.front();pThreadPoolObj->_JobQueue.pop();assert(pJob);}LeaveCriticalSection(&pThreadPoolObj->_csWorkQueue);//受到结束线程信号 确定是否结束线程(结束线程信号 && 是否还有工作)if(wr == WAIT_OBJECT_0 + 2 && !fHasJob)break;if(fHasJob && pJob){InterlockedIncrement(&pThreadPoolObj->_lRunningNum);pThread->_dwLastBeginTime = GetTickCount();pThread->_dwCount++;pThread->_fIsRunning = true;pJob->_pFunc(pJob->_pPara); //运行用户作业delete pJob;pThread->_fIsRunning = false;InterlockedDecrement(&pThreadPoolObj->_lRunningNum);}}//删除自身结构EnterCriticalSection(&pThreadPoolObj->_csThreadVector);pThreadPoolObj->_ThreadVector.erase(find(pThreadPoolObj->_ThreadVector.begin(), pThreadPoolObj->_ThreadVector.end(), pThread));LeaveCriticalSection(&pThreadPoolObj->_csThreadVector);delete pThread;InterlockedDecrement(&pThreadPoolObj->_lThreadNum);if(!pThreadPoolObj->_lThreadNum) //所有线程结束SetEvent(pThreadPoolObj->_EventComplete);return 0;}//调用用户对象虚函数static void CallProc(void *pPara){CallProcPara *cp = static_cast<CallProcPara *>(pPara);assert(cp);if(cp){cp->_pObj->DoJob(cp->_pPara);delete cp;}}//用户对象结构struct CallProcPara{ThreadJob* _pObj;//用户对象void *_pPara;//用户参数CallProcPara(ThreadJob* p, void *pPara) : _pObj(p), _pPara(pPara) { };};//用户函数结构struct JobItem{void (*_pFunc)(void *);//函数void *_pPara; //参数JobItem(void (*pFunc)(void *) = NULL, void *pPara = NULL) : _pFunc(pFunc), _pPara(pPara) { };};//线程池中的线程结构struct ThreadItem{HANDLE _Handle; //线程句柄ThreadPool *_pThis; //线程池的指针DWORD _dwLastBeginTime; //最后一次运行开始时间DWORD _dwCount; //运行次数bool _fIsRunning;ThreadItem(ThreadPool *pthis) : _pThis(pthis), _Handle(NULL), _dwLastBeginTime(0), _dwCount(0), _fIsRunning(false) { };~ThreadItem(){if(_Handle){CloseHandle(_Handle);_Handle = NULL;}}};std::queue<JobItem *> _JobQueue; //工作队列std::vector<ThreadItem *> _ThreadVector; //线程数据CRITICAL_SECTION _csThreadVector, _csWorkQueue; //工作队列临界, 线程数据临界HANDLE _EventEnd, _EventComplete, _SemaphoreCall, _SemaphoreDel;//结束通知, 完成事件, 工作信号， 删除线程信号long _lThreadNum, _lRunningNum; //线程数, 运行的线程数};#endif

 

调用方法

void threadfunc(void *p)

{

     YourClass* yourObject = (YourClass*)    p;

 //...
}
 ThreadPool tp;
 for(i=0; i<100; i++)
  tp.Call(threadfunc);

ThreadPool tp(20);//20为初始线程池规模

 tp.Call(threadfunc, lpPara);

使用时注意几点：

1. ThreadJob  没什么用，直接写线程函数吧。 

2. 线程函数（threadfunc）的入口参数void* 可以转成自定义的类型对象，这个对象可以记录下线程运行中的数据，并设置线程当前状态，以此与线程进行交互。

3. 线程池有一个EndAndWait函数，用于让线程池中所有计算正常结束。有时线程池中的一个线程可能要运行很长时间，怎么办？可以通过线程函数threadfunc的入口参数对象来处理，比如：

class YourClass {

  int cmd; // cmd = 1是上线程停止计算，正常退出。

};

threadfunc(void* p) {

  YourClass* yourObject = (YourClass*)p;

  while (true) {

    // do some calculation

    if (yourClass->cmd == 1)

      break;

  }

}

在主线程中设置yourClass->cmd = 1，该线程就会自然结束。

很简洁通用的线程池实现。

http://blog.csdn.net/revv/archive/2008/11/07/3248424.aspx